Anchoring of nickel (II) kojic acid in functionalized Si-MCM‐41 matrix: a effective nanocatalyst for the catalytic clean synthesis of dihydropyrano[3,2-b]chromenediones

Green solventless preparation of dihydropyrano[3,2-b]chromenediones was developed by a three-component reaction (3-CR) of dimedone, different aldehydes, and kojic acid that catalyzed with nano-silica-MCM‐41‐kojic acid‐Ni as a reusable, efficient, and high yielding nanocatalyst. The reactions were completed at 100 °C in 20 min using 5 mg of nanocatalyst under neat conditions to synthesize 1 mmol of the product in high yield. Nano-silica-MCM‐41‐KA‐Ni was prepared by the post-grafting method and characterized using XRD, ICP, EDX, TGA, DTA, SEM, and TEM analyses. The used nanocatalyst was easily recovered using centrifugation and effectively reutilized 5-recycle without considerable changes in its silicate structure mesoporosity and an important decrease in its catalytic activity.